Math Problem Statement

(a) The diagram shows the graphs of y = 2x and y = 2x + 1 . (i) State the gradient of the line y = 2x + 1 . (ii) Find the value of x such that x > 0 and 2x + 1 = 2x . Answer (a)(i) .............................................. [1] (ii) x = ....................................... [1] (b) The diagram shows the graph of y = kax . State the value of (i) k , (ii) a. Answer (b)(i) k = ....................................... [1] (ii) a = ....................................... [1] For Examiner’s Use For Examiner’s Use © UCLES 2004 7 0 1 123 2 3 4

Solution

Let's break down the problem step by step.

Part (a)

We are given two equations:

  1. y=2xy = 2x
  2. y=2x+1y = 2x + 1

(a)(i) Gradient of the line y=2x+1y = 2x + 1

The general form of a linear equation is y=mx+cy = mx + c, where:

  • mm is the gradient (slope),
  • cc is the y-intercept.

For the equation y=2x+1y = 2x + 1, we can directly see that the gradient m=2m = 2.

Answer (a)(i): The gradient is 2.

(a)(ii) Solve 2x+1=2x2x + 1 = 2x

We need to find the value of xx such that x>0x > 0 and 2x+1=2x2x + 1 = 2x.

  1. Subtract 2x2x from both sides: 2x+12x=2x2x2x + 1 - 2x = 2x - 2x This simplifies to: 1=01 = 0

This is a contradiction, which means there is no value of xx that satisfies the equation 2x+1=2x2x + 1 = 2x when x>0x > 0.

Answer (a)(ii): There is no solution for x>0x > 0.

Part (b)

We are given the equation y=kaxy = k a^x, and we need to find the values of kk and aa.

(b)(i) Value of kk

kk represents the initial value when x=0x = 0. Based on the diagram (which I assume shows an exponential graph), the value of yy when x=0x = 0 is the constant kk. From the general form y=kaxy = k a^x, substitute x=0x = 0: y=ka0=k(1)=ky = k a^0 = k(1) = k So, y(0)=ky(0) = k, which is the y-intercept of the graph.

You would typically find this value from the graph (not given in the problem), but it’s the initial value when x=0x = 0.

Answer (b)(i): The value of kk depends on the y-intercept, which can be read off from the graph.

(b)(ii) Value of aa

aa is the base of the exponential function, which can be determined by observing how the graph increases. If the graph's shape shows rapid growth, a>1a > 1, and if it shows decay, 0<a<10 < a < 1. The exact value of aa also needs to be read off the graph based on the nature of the curve.

Answer (b)(ii): The value of aa depends on the growth rate of the exponential function, which is read from the graph.


Would you like me to go into more details on any part of this explanation or help with another example?

5 related questions:

  1. What is the difference between a gradient and y-intercept in linear equations?
  2. How do we identify contradictions in algebraic equations?
  3. How does the value of aa affect the shape of an exponential graph?
  4. What happens to an exponential graph when kk is negative?
  5. Can the equation 2x+1=2x2x + 1 = 2x have a solution if we remove the constraint x>0x > 0?

Tip:

When solving linear equations, always check for contradictions or undefined results when simplifying!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Equations
Exponential Functions

Formulas

y = mx + c
y = k * a^x

Theorems

Slope-Intercept Form of a Line
Properties of Exponential Growth

Suitable Grade Level

Grades 9-10